A "partypooper" is typically someone who ruins the fun and enjoyment of a social gathering. Some synonyms for a partypooper include "killjoy," "spoilsport," "wet blanket," "buzzkill," and "stick-in-the-mud." A "killjoy" is someone who appears to take no pleasure in an enjoyable event or occasion. A "spoilsport" is someone who ruins the good mood or positive energy of something. Someone referred to as a "wet blanket" is someone who is a dampener on the excitement or enjoyment of others. A "buzzkill" is someone who suddenly kills the positive buzz or energy of a gathering, and a "stick-in-the-mud" is someone who is resistant to trying new things and having fun.